Oak tree named ‘Tabor’

ABSTRACT

A new and distinct hybrid oak named ‘Tabor’ characterized by its broad-oval growth habit, dark, glossy green mildew resistant foliage, strong wood, orange-red fall color, and hybrid vigor.

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar of a F₁hybrid oak tree botanically known as Quercus robur×Quercus alba andreferred to by the name ‘Tabor’. The parent tree is growing in acultivated area at the home of Earl Cully, 846 Hoagland Road,Jacksonville, Ill. 62650 in Morgan County, Township 14 north, Range 10east. The ‘Tabor’ oak was selected from acorns collected at Carle Parkin Urbana, Ill. The acorns were planted in the fall of 1975 and the‘Tabor’ oak was selected from this cohort of seedlings.

BRIEF SUMMARY OF THE INVENTION

The ‘Tabor’ cultivar displays a broad-oval crown form, a straightcentral leader, and extremely glossy, dark green leaves. The parent treeis approximately 54 feet (16.5 meters) in height with a 48.5 foot (14.8meters) spread after 32 years of growth. ‘Tabor’ shows hybrid vigor withgrowth having averaged 1.7 feet (52 cm) per year during this time. Ithas come through several ice storms and high wind events with noobserved breakage of any branches indicating a very strong angle ofbranching and wood structure. ‘Tabor’ has proven winter hardy in theU.S.D.A. zone 5b in which it has been growing and has survived lowtemperatures of minus 28° F. (−33° C.) and unusual spring and fallfreezes without any damage. With white oak (hardy in zone 3b to 9) asone of its parents, it would be reasonable to assume winter hardinessinto zone 4b.

‘Tabor’ hybrid oak lends itself well to park, street tree, home lawnplantings where a large long lived tree would be desired. The unusualorange-red autumnal coloration distinguishes the ‘Tabor’ cultivar fromother native oak species and cultivars in the eastern United States.

The pistillate parent of the ‘Tabor’ cultivar was determined to beEnglish oak (Quercus robur) and the staminate parent has been determinedto be white oak (Quercus alba). This unique heritage has resulted insome botanical traits that are characteristic of one or both parentswhile other traits are intermediate. The leaves are approximately thesame size as white oak but an average leaf has 11 to 13 lobes which ismore typical of English oak. The lobes of the ‘Tabor’ cultivar arelonger and more obtuse than is typical for English oak which have short,rounded lobes. ‘Tabor’ oak has an intermediate peduncle length thatvaries from 1.8 to 4.3 cm while a typical white oak has a sessile to 1.3cm long peduncle, and English oak has a peduncle length of 2.5 cm to10.6 cm. The autumn coloration is an orange-red color which differs fromEnglish oak and white oak. English oak foliage typically has a yellow tobrown fall color, and white oak foliage turns burgundy-red and thenpurple, but the intermediate orange-red autumnal color of ‘Tabor’demonstrates its hybrid heritage.

Clones of the ‘Tabor’ demonstrate hybrid vigor and typically grow 5 to 6feet in height after being grafted onto established two year-old swampwhite oak (Quercus bicolor) rootstock with 90-95% success. This cultivarhas been propagated by side-veneer and cleft grafting. Chip-budding hasalso been used to propagate this plant. Propagation has been performedat 846 Hoagland Road, Jacksonville, Ill. 62650 and in two differentwholesale nurseries in Oregon.

DETAILED BOTANICAL DESCRIPTION

In the following description, color references are made to The RoyalHorticultural Society Colour Chart.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying colored photographs illustrate the appearance and colorof the new ‘Tabor’ cultivar hybrid oak tree. These photographs show thecolor as is reasonably possible to obtain in colored reproductions ofthis type. Actual foliage colors may differ slightly due to lightreflectance.

FIG. 1 depicts the initially discovered tree named ‘Tabor’ in summerfoliage showing the broad, oval crown form and highly glossy, diseaseand powdery mildew free dark green foliage.

FIG. 2 depicts the ‘Tabor’ cultivar without foliage; thus, revealing itsbranching structure.

FIG. 3 depicts the Tabor cultivar in autumn showing the orange-redcolor.

FIG. 4 depicts a clone of the ‘Tabor’ cultivar illustrating the samebroad, oval crown form as the parent tree.

FIG. 5 depicts the powdery mildew resistant, dark green, glossy foliageof the ‘Tabor’ oak.

FIG. 6 depicts the autumnal leaf color (orange-red 32B and orange 26A).

FIG. 7 depicts a twig, including terminal and lateral buds of the‘Tabor’ oak.

FIG. 8 depicts mature (brown) acorns of the ‘Tabor’ cultivar in earlyautumn.

THE PLANT Tree, Hybrid Oak

-   Name: Cultivar ‘Tabor’.-   Parentage:    -   -   Seedling or sport.—Seedling.        -   Seed parent.—Quercus robur.        -   Pollen parent.—Quercus alba.-   Classification: Quercus robur×Quercus alba.-   Discovered: This seedling was selected from a row of seedlings in a    cultivated area at the home of Earl Cully located at 846 Hoagland    Road, Jacksonville, Ill. 62650, Morgan County, Township 14,    Range 10. Presently, the tree is being propagated by chip budding or    grafting onto two-year old swamp white oak (Quercus bicolor)    seedlings at 846 Hoagland Road, Jacksonville, Ill. 62650 and at a    two wholesale nurseries in Oregon.-   Form: Tree.-   Shape: Broad oval.-   Height: 16.46 meters, 54 feet.-   Spread: 14.78 meters, 48.5 feet.-   Trunk size: Diameter at breast height (d.b.h) =58.6 cm, 23.1 inches    (as measured at 1.37 meters, 54 inches above ground level).-   Trunk base shape: Cylindrical.-   Growth rate: Moderate to fast.-   Strength: Excellent, no evidence of breakage.-   Age:32.-   Bark: furrowed vertically, breaking into long, blocky ridges.    -   -   Alignment of pattern.—Vertical furrows.        -   Texture of bark.—Moderately rough does not flake easily.        -   Exfoliation.—no exfoliation.        -   Size of bark pattern.—Plates (19.0-6.4 cm) average=9.3 cm            long by (3.2-1.3 cm) average=2.2 cm wide.-   Trunk bark color: Mostly grey 156A, with some grey-green 197A, and    grey-green 198A.-   Branches:    -   -   Angle of attachment.—Most branches varied between 60°-90°,            with some upper branches at 30°.        -   Spacing of branches.—Moderately dense approximately 32 cm to            91cm between whorls of branches.        -   Bark color.—Grey (156B and C).        -   Bark texture.—Smooth on branches less than 5 cm diameter,            with furrows developing on larger branch diameters.        -   Bark exfoliation.—No exfoliation observed.        -   Small twig bark.—(<0.7 cm diameter) (growing season)            grey-green (195A,197A), grey-orange (177A), and grey (201A)            (dormant season) grey-purple (183A), grey-green (197C), and            grey (201A) Twig texture: Smooth overall but has small,            warty lenticels.        -   Lenticels.—Small (0.05-0.1 cm), average=0.05 cm, round to            oval orange-white (159B & C).        -   Buds.—Small triangular in shape (0.16 cm-0.79 cm),            average=0.49 cm, scaled with a smooth texture and a fine            pubescence on bud scales. The bud scales are arranged in an            imbricate pattern with short grey-white (156D) hairs on the            edge of the scales.-   Leaves:    -   -   Petiole.—Length: (0.79-3.8 cm), average=2.3 cm. Color:            Yellow-green (146D & C). Texture: smooth with no hairs and            no warts present.        -   Lamina.—Length: (7.3 cm-24.6 cm), average=16.6 cm. Width:            (4.45 cm-12.1 cm), average=7.0 cm. Form: Lamina obovate to            oblanceolate. Shape of lamina base: Cuneate. Shape of lamina            apex: Acute. Margin: Lobed. Texture: Membranous, glossy            smooth upper surface. Quantity: Abundant. Color: Summer            (upper) green (135A & B) (lower) green (136C) autumnal            (upper) orange-red (32B), orange (26A) (lower) grey-orange            (177D) grey-red (180D). Ribs and veins: 8 to 12 pairs of            prominent veins yellow-green (150D); pinnate pattern of            venation.-   Flowers: Imperfect, monoecious; staminate aments are pendent,    clustered with approximately 6 catkins per cluster, length 3.0-7.0    cm yellow-green (154B and 154 C); pistillate flowers are found in    the axils of the emerging new leaves, ovary surrounded by a calyx    0.1-0.3 cm in length, color yellow-green (154A).-   Fruit: Nut (acorn), acorn color of mature acorn is grey-orange (176A    & 177A), length (cap and acorn) (4.0 cm-2.54 cm) average=3.4 cm, cap    width (2.2 cm-1.9 cm) average=2.0 cm; length of the acorn (3.5    cm-2.1 cm) average=3.0 cm; cap length (1.4 cm-1.1 cm) average=1.3    cm; cap depth (1.3 cm-0.8 cm) average=1.0 cm; mature cap color is    grey-brown (199B), immature cap color is a mixture of yellow-green    (147C and 143C); peduncle length (4.3 cm-1.8 cm) average=2.7 cm;    peduncle color grey-orange (166A); on average each peduncle held one    developed acorn; imbricate scales on cap have a rough, warty    texture; cap encloses 30% to 25% of the acorn.    Has this plant ever been offered for sale? No.    Compare this new variety with others of the same species and with    its parents or parents; state the distinguishing characteristics of    the new cultivar and its advantages.

This tree has a highly symmetrical broad-oval crown with extremelyglossy, dark green leaves. The leaves posses an unusual shape exhibitingdistinctive characteristics of the two different parent species Quercusrobur and Quercus alba. The foliage of ‘Tabor’ most closely resembleswhite oak in size of the foliage and general outline of the leaf, butEnglish oak shows its influence with a greater number of lobes per leafthan white oak and a longer acorn peduncle than white oak. The bark of‘Tabor’ is also darker than white oak. The ‘Tabor’ hybrid oak has anorange-red autumnal coloration in contrast to red and burgundy fallcolor of white oak, or the yellow-brown fall color of English oak. The‘Tabor’ hybrid oak differs from the Crimson Spire hybrid oak(Quercus×bimundorum) by having orange-red fall color instead of red anda broad oval crown form instead of columnar. ‘Tabor’ oak also differsfrom the ‘Long’ U.S. Plant Pat. No. 12,673 hybrid oak (Quercus×warei)and the ‘Nadler’ U.S. Plant Pat. No. 17,604 hybrid oak (Quercusxwarei)by having a broad crown form in contrast to the medium-oval crown fromof ‘Long’ and the narrow columnar form of ‘Nadler’. ‘Tabor’ hybrid oakshares the broad-oval crown form of the ‘Clemons’ U.S. Plant Pat. No.11,431 hybrid oak. The orange-red fall color of ‘Tabor’ differs from theyellow-brown autumnal color of ‘Clemons’, ‘Long’, and ‘Nadler’ hybridoaks.

1. A new and distinct variety of hybrid oak tree Quercus robur×Quercusalba as illustrated and described herein.